[Template] avoid thousands of MissingPropertyExceptions

[xael-fry]

From @angryziber in #1039:

Binding can only contain variables (basically, a Map), not properties.

If groovy doesn't find a variable, it throws a MissingPropertyException populating the stacktrace.

GroovyTemplate.getProperty() first calls the getVariable(), if it throws (happens very often if you have optional bindings), then it catches and delegates to getProperty(), that does some slow work itself again.

This small change avoids these excessive exceptions with stacktraces on every missing variable access.

[angryziber]

Do you have any examples of which code breaks?

We found that without this change, sometimes you could #{set} something and then use the value with just ${}

[xael-fry]

@angryziber As I said in #1039, I am doing a PR with tests for that.
Yes this is the goal of set, so you mean that with your change with cannot do it anymore.

[angryziber]

I thought the goal of set is to influence get with the same name? In most cases they lived in separate namespaces, afaik. But I found one case, where the set value was accessible via ${} before, but not anymore.

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On Wed, 28 Dec 2016, 02:50 Alexandre Chatiron, ***@***.***> wrote: @angryziber <https://github.com/angryziber> As I said in #1039 <#1039>, I am doing a PR with tests for that. Yes this is the goal of set, so you mean that with your change with cannot do it anymore. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#1067 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA11YJ6VWC3uhQgDKJxOQ-UYBivNuvzQks5rMbJogaJpZM4LV-vH> .

[xael-fry]

Yes I could be used by Get, but as nothing block to used it another way, we cannot block now a behavior that was accepted before, or it will affect users projects, or we should do it in a major revision.
But what do you mean by But I found one case, where the set value was accessible via ${} before, but not anymore., in your project, in play/examples?

[angryziber]

In my project. But do you say that that was an intended behaviour, #{set} and then ${} instead of #{get}?

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On Thu, 29 Dec 2016, 02:45 Alexandre Chatiron, ***@***.***> wrote: So we cannot block now a behavior that was accepted before, or it will affect users projects. But what do you mean by But I found one case, where the set value was accessible via ${} before, but not anymore., in your project, in play/examples? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#1067 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA11YBHeno9jl4M96Yy0oWbed0-ORN-Qks5rMwKwgaJpZM4LV-vH> .

[xael-fry]

No I just say that the initial behavior was to used #{set} /#{get} but as we allowed to used ${} in the past, I am not sure we can remove this behavior in the minor release